The risk management plugin is only internationalizated with english and spanish languages.
If you are using redmine with other language, you can see a translation missing error.
Change your language to english or copy the "en.yml" file from redmine_risks/lang directory and rename it to your language:

de.yml for german
it.yml for italian
fr.yml for french
ja.yml for japanese
...

Now, you can translate the plugin to your language by editing this file.